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Rearrange code a bit

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11793 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2004-02-24 05:54:22 +00:00
parent 0d56008f53
commit e14ea0804a
1 changed files with 27 additions and 30 deletions
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57
lib/Transforms/Utils/SimplifyCFG.cpp
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@@ -301,36 +301,6 @@ bool llvm::SimplifyCFG(BasicBlock *BB) {
assert(BB->getTerminator() && "Degenerate basic block encountered!"); assert(BB->getTerminator() && "Degenerate basic block encountered!");
assert(&BB->getParent()->front() != BB && "Can't Simplify entry block!"); assert(&BB->getParent()->front() != BB && "Can't Simplify entry block!");
// Check to see if the first instruction in this block is just an unwind. If
// so, replace any invoke instructions which use this as an exception
// destination with call instructions.
//
if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator()))
if (BB->begin() == BasicBlock::iterator(UI)) { // Empty block?
std::vector<BasicBlock*> Preds(pred_begin(BB), pred_end(BB));
while (!Preds.empty()) {
BasicBlock *Pred = Preds.back();
if (InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator()))
if (II->getUnwindDest() == BB) {
// Insert a new branch instruction before the invoke, because this
// is now a fall through...
BranchInst *BI = new BranchInst(II->getNormalDest(), II);
Pred->getInstList().remove(II); // Take out of symbol table
// Insert the call now...
std::vector<Value*> Args(II->op_begin()+3, II->op_end());
CallInst *CI = new CallInst(II->getCalledValue(), Args,
II->getName(), BI);
// If the invoke produced a value, the Call now does instead
II->replaceAllUsesWith(CI);
delete II;
Changed = true;
}
Preds.pop_back();
}
}
// Remove basic blocks that have no predecessors... which are unreachable. // Remove basic blocks that have no predecessors... which are unreachable.
if (pred_begin(BB) == pred_end(BB)) { if (pred_begin(BB) == pred_end(BB)) {
//cerr << "Removing BB: \n" << BB; //cerr << "Removing BB: \n" << BB;
@@ -473,6 +443,33 @@ bool llvm::SimplifyCFG(BasicBlock *BB) {
return true; return true;
} }
} }
} else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->begin())) {
// Check to see if the first instruction in this block is just an unwind.
// If so, replace any invoke instructions which use this as an exception
// destination with call instructions.
//
std::vector<BasicBlock*> Preds(pred_begin(BB), pred_end(BB));
while (!Preds.empty()) {
BasicBlock *Pred = Preds.back();
if (InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator()))
if (II->getUnwindDest() == BB) {
// Insert a new branch instruction before the invoke, because this
// is now a fall through...
BranchInst *BI = new BranchInst(II->getNormalDest(), II);
Pred->getInstList().remove(II); // Take out of symbol table
// Insert the call now...
std::vector<Value*> Args(II->op_begin()+3, II->op_end());
CallInst *CI = new CallInst(II->getCalledValue(), Args,
II->getName(), BI);
// If the invoke produced a value, the Call now does instead
II->replaceAllUsesWith(CI);
delete II;
Changed = true;
}
Preds.pop_back();
}
} }
// Merge basic blocks into their predecessor if there is only one distinct // Merge basic blocks into their predecessor if there is only one distinct